CALL it the Big Flush 2, and this time the sequel promises to be much bigger than the original.

Portland city officials said they are flushing away 143 million litres of treated water for the second time in less than three years because someone urinated into a city reservoir.

In June 2011, the city drained a 28 million-litre reservoir at Mount Tabor in southeast Portland. This time, 143 million litres from a different reservoir at the same location will be discarded after a 19-year-old was videotaped in the act of urinating.

“The basic commandment of the Water Bureau is to provide clean, cold and constant water to its customers,” Portland Water Bureau administrator David Shaff said. “And the premise behind that is we don’t have pee in it.”

The open reservoirs hold water that has already been treated and goes directly into mains for distribution to customers.

The urine poses little risk — animals routinely deposit waste without creating a public health crisis — but Shaff said he doesn’t want to serve water that was deliberately tainted.

“There is at least a perceived difference from my perspective,” Shaff said. “I could be wrong on that, but the reality is our customers don’t anticipate drinking water that’s been contaminated by some yahoo who decided to pee into a reservoir.”

Water-quality test samples have been taken from the reservoir, with the results due tomorrow. The water will be drained into the sewage system, eventually reaching a treatment plant before it’s dumped into the Columbia River.

In the meantime, Shaff said the city has plenty of water to meet demand.

“It’s easy to replace those 38 million gallons (143 million litres) of water,” Shaff said. “We’re not in the arid Southwest. We’re not in drought-stricken parts of Texas or Oklahoma.”

The incident occurred shortly after 1am, when Water Bureau security personnel noticed three men on camera at Mount Tabor Reservoir No. 5. One was seen on video urinating through an iron fence, officials said. Minutes later, two other young men attempted to scale the fence.

The three men, whose names have not been released, were cited for trespassing and excluded from Mount Tabor Park. A 19-year-old was cited for public urination.

The kidney-shaped reservoir built in 1911 is drained for cleaning each spring and fall. The spring draining was done about three weeks ago, the Water Bureau said.

The reservoir is one of five the city is in the process of replacing with underground storage to comply with federal regulations.

Floy Jones, co-founder of the group Friends of the Reservoirs, criticised the decision to drain the reservoir, saying there’s no evidence any urine reached the water and it wouldn’t harm anyone if it did.

“It’s extremely wasteful,” she said.

The man who urinated into Portland’s water supply in June 2011 eventually pleaded guilty to misuse of a reservoir and was sentenced to community service.

Because someone urinated into the water reservoir.

Surprising still, this isn’t the first time this has happened.

The latest incident took place about 1am on Wednesday (local time). Cameras captured three teens near the Mount Tabor Reservoir No. 5. One of them approached the iron fence and apparently got close enough to relieve himself directly into the reservoir.

The three teens were apprehend, and the 50-million-gallon reservoir was taken offline for testing.

Thanks to the teens, the Portland Water Bureau will have to dump 38 million gallons of drinking water, said administrator David Shaff.

“Our customers have an expectation that their water is not deliberately contaminated,” he said.

All three teens received citations for trespassing; one was cited for public urination.

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